Abstract: A novel vehicle power supply system is suggested which receives its voltage supply from a starter/generator which can be used as a generator in normal operation and as a starter when starting, wherein the starter/generator is connected with a 24 volt ring mains as well as with a 24 volt battery via a pulse inverter and a 300 volt DC intermediate circuit and a bidirectional converter. Additional consumers can be supplied with higher voltages than 24 volts and electric control devices can be supplied with voltage, possible via additional converters, from the bidirectional push-pull converter and the 300 volt DC intermediate network. In addition, this vehicle power supply system contains a plug receptacle with a 220 volt 50 Hz voltage.